Brian Vicente, co-author of Amendment 64, speaks at an event promoting Proposition AA, which would enact a 15 percent excise tax on the wholesale distribution of marijuana as well as a 10 percent sales tax at the retail level. (Brennan Linsley, The Associated Press)

We were disappointed to see that one of the most established organizations in support of marijuana legalization opposes Proposition AA, which would enact state excise and sales taxes on recreational pot.

The Colorado chapter of NORML, the National Organization for the Reform of Marijuana Laws, said in a statement that it was against Proposition AA because the measure would impose “excessive taxation” on the sale of recreational marijuana, which becomes legal in January.

If enacted by voters in November, Proposition AA would impose a 15 percent state excise tax on marijuana, levied on its wholesale price, and then a 10 percent special state sales tax on retail transactions. The legislature could raise the sales tax up to 15 percent or lower either tax, but neither tax could ever top 15 percent.

One estimate contends the state could generate up to $91 million a year off the taxes on pot, though official estimates from the legislature say it would be closer to $60 million.

All of the estimates are based on scant information. The recreational pot industry is new, it will be largely confined to Denver, and it’s unclear just how much pot will be sold.

Two things are abundantly clear, though. First, it is imperative the state properly regulate the sale of recreational marijuana, which is still illegal under federal law and which other states will closely watch. Second, the state has done a horrible job of regulating medical marijuana precisely because of underfunding.

“We believe that if Measure AA fails, there will still be adequate funds to effectively regulate recreational marijuana,” NORML said in a statement, referring to licensing fees. “We believe our state and local regulators can and should meet the challenge of marijuana regulation through the efficient management of their budgeted funds.”

But a state audit specifically said that licensing fees alone were grossly insufficient to do the job.

We also disagree with those who say the taxes will drive pot back to the black market. At some level they would, but we think most buyers would be plenty willing to pay these taxes in exchange for legality.